Cumulative Mutations of Ubiquitin Acceptor Sites in Human Immunodeficiency Virus Type 1 Gag Cause a Late Budding Defect

• DOI: 10.1128/jvi.02177-05
• Publication Date: 2006-06-15T00:21:50Z
• Authors: Eva Gottwein; Stefanie Jäger; Anja Habermann; Hans-Georg Kräus...
• Keywords: Budding; Group-specific antigen

The p6 domain of human immunodeficiency virus type 1 (HIV-1) Gag has long been known to be monoubiquitinated. We have previously shown that the MA, CA, and NC domains are also monoubiquitinated at low levels (E. Gottwein H. G. Krausslich, J. Virol. 79:9134-9144, 2005). While several lines evidence support a role for ubiquitin in release, relevance ubiquitination is unclear. To directly address function ubiquitination, we constructed variants which lysine residues NC, SP2, were mutated arginine either individual or combination. Using these mutants, showed addition p6, SP2 mono- di-ubiquitinated comparable those other domains. Replacement all only one had minor effects on while cumulative mutations resulted an accumulation late budding structures, as observed by electron microscopy analysis. Strikingly, replacement downstream CA led significant reduction release kinetics fivefold viral structures compared wild-type levels. These results indicate vicinity important HIV-1 budding, no specific residue may needed can functionally substitute. This consistent with being involved transient protein interaction network site.